http://www.medications.com/effect/view/42009 My son Emmett was put on Omnicef for pneumonia and ear infection. On the second day of being on this drug he had terrible diarrhea, black and watery and he would scream every time he was pooping. He wouldn't sit and would cry if you tried to lay him down to Fri, 19 Jun 2009 19:59:33 -0400 http://www.medications.com/effect/view/42009?item=20785 I would almost guarantee This woman was feeding her son a dairy product like yogurt either with the omnicef or within hours of him taking it. This would explain everything. The horrible diarrhea and stomach pain and the fact that his infection progressed http://www.medications.com/effect/view/42009?item=20785